The original aim of this project was to define the effect of puberty on the etiology and progression of diabetic nephropathy. During the course of this project, we identified cardiovascular abnormalities which were associated with increased glomerular filtration rate and microalbuminuria, suggesting that the complications of IDDM in these two organ systems develop in a parallel fashion. We are now studying the sequence of appearance and interrelationships of preclinical cardiac, renal and hypertensive disease.